SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9528989065399a1b18d7251eabbecb02bd778b7f0f695c33f4c13d7f79739c73' 
  AND token = '9JkrtYIhPIJqkpSmRSUJkQJA/AZfWMXIMVW1OTxHVvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}